Do not make the calling of the Messenger among yourselves like the call of one of you to another. Already Allah knows those of you who slip away, concealed by others. So let those who oppose the Prophet’s command beware, lest fitnah strike them or a painful punishment. [24:63]

In his famous book of tafsir, Abu’l-Fidaa’ Ismaa’eel ibn Kathir wrote the following regarding this ayah:

al-Dhahhaak reported from ibn ‘Abbas: People used to say, “O Muhammad! O Abu’l-Qaasim!”, so Allah forbade them from doing that out of reverence for His prophet (ﷺ). He told them to instead say, “O Messenger of Allah! O Prophet of Allah!”.

Do not make the calling of the Messenger among yourselves like the call of one of you to another

Muqaatil ibn Hayyaan said: Do not address him by name when you call him, such as saying, “O Muhammad!”, and do not say, “O ibn ‘Abdullah!”; rather, hold him in high regard and say, “O Prophet of Allah! O Messenger of Allah!”

O you who have believed, do not raise your voices above the voice of the Prophet or be loud to him in speech like the loudness of some of you to others, lest your deeds become worthless while you perceive not. * Indeed, those who lower their voices before the Messenger of Allah – they are the ones whose hearts Allah has tested for righteousness. For them is forgiveness and great reward. * Indeed, those who call you, [O Muhammad], from behind the chambers – most of them do not use reason. * And if they had been patient until you [could] come out to them, it would have been better for them. But Allah is Forgiving and Merciful. [49:2-5]

Do not make the calling of the Messenger among yourselves like the call of one of you to another

means: do not believe that the Prophet’s supplication against others is like the supplication of anyone else. For his supplication is answered, so beware lest he supplicate against you and you be destroyed. Ibn Abi Haatim transmitted this from ibn ‘Abbas, Hasan al-Basri, and ‘Atiyyah al-‘Awfi. And Allah knows best

قَدْ يَعْلَمُ اللَّـهُ الَّذِينَ يَتَسَلَّلُونَ مِنكُمْ لِوَاذًا

Allah already knows those of you who slip away, concealed by others.

Muqaatil ibn Hayyan said: these ones are the munaafiqoon. The speech on the Day of Jumu’ah – i.e. the khutbah – used to weigh heavily on them, so they would hide behind some of the Sahabah – the Companions of Muhammad (ﷺ) – until they could sneak out of the masjid. And it is not appropriate for a man to leave the masjid on Jumu’ah after the khutbah has begun except if he is given permission by the Prophet (ﷺ). If someone wanted to leave, then he would make a gesture to the Prophet (ﷺ) with his finger and he would grant him permission without the man needing to speak, because if a man were to speak while the Prophet (ﷺ) was delivering the khutbah, then that would invalidate his Jumu’ah prayer.

فَلْيَحْذَرِ‌ الَّذِينَ يُخَالِفُونَ عَنْ أَمْرِ‌هِ

So let those who oppose the Prophet’s command beware

meaning: those who dissent from the command of Allah’s messenger (ﷺ). That refers to his path, his manhaj, his way, his sunnah, and his sharee’ah. For all statements and actions should be weighed against the standard of his statements and actions; whatever is in agreement with them is accepted, and whatever differs from that will be rejected from the one who said or did it, regardless of who that person is. This has been affirmed in the Saheehayn and elsewhere, that Allah’s messenger (ﷺ) said, “Whoever does an action which is not in agreement with this affair of ours, then it is rejected.”